Insects can squeeze through the smallest cracks, fit comfortably into constricted spaces and survive in extreme environments. Basically, there are not many spaces that are out-of-bounds to an insect.
That is the reason why scientists at the University of Pittsburgh have designed miniature bug-inspired robots that can perform tasks in hard-to-reach spaces and hostile environments.
These robots could be used to access confined areas for imaging or environmental evaluation, take water samples, or perform structural evaluations. Anywhere you want to access confined places—where a bug could go but a person could not—these machines could be useful.
Junfeng Gao, Study Lead and PhD Student in Industrial Engineering, Swanson School of Engineering, University of Pittsburgh
For a number of creatures under a certain size — like mantis shrimp, trap-jaw ants and fleas — jumping across a surface saves them more energy than crawling. Those spontaneous movements were simulated in the robots, which are composed of polymeric synthetic muscle.
It’s akin to loading an arrow into a bow and shooting it—the robots latch on to build up energy and then release it in an impulsive burst to spring forward. Usually, actuation in the artificial muscles we work with is fairly slow. We were drawn to the question, ‘How do we take this artificial muscle and use it to generate a jumping actuation rather than slow actuation?’
M. Ravi Shankar, Professor of Industrial Engineering, University of Pittsburgh
The answer lay in the relationship between geometry and molecular order.
The curved composite shape of the polymer muscle allows it to build energy when it is powered. The way the molecules are aligned in the muscle draws inspiration from the natural world, where their combined actuation builds energy into the structure. This is accomplished using no more than a few volts of electricity.
Mohsen Tabrizi, Study Co-Author and PhD Student in Industrial Engineering, Swanson School of Engineering, University of Pittsburgh
The flexible movement and lightweight structure allow the robots — which are approximately the size of a cricket — to travel along moving surfaces like sand as effortlessly as hard surfaces and even to jump across water.
Ravi Shankar’s lab led the research. The study has been published in Advanced Materials Technologies.
Gao, J., et al. (2022) Molecularly Directed, Geometrically Latched, Impulsive Actuation Powers Sub-Gram Scale Motility. Advanced Materials Technologies. doi.org/10.1002/admt.202100979.